RT Journal Article SR Electronic T1 Insights into the secondary structural ensembles of the full SARS-CoV-2 RNA genome in infected cells JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.06.29.178343 DO 10.1101/2020.06.29.178343 A1 Tammy C. T. Lan A1 Matthew F. Allan A1 Lauren E. Malsick A1 Stuti Khandwala A1 Sherry S. Y. Nyeo A1 Yu Sun A1 Junjie U. Guo A1 Mark Bathe A1 Anthony Griffiths A1 Silvi Rouskin YR 2021 UL http://biorxiv.org/content/early/2021/02/19/2020.06.29.178343.abstract AB SARS-CoV-2 is a betacoronavirus with a single-stranded, positive-sense, 30-kilobase RNA genome responsible for the ongoing COVID-19 pandemic. Currently, there are no antiviral drugs with proven efficacy, and development of these treatments are hampered by our limited understanding of the molecular and structural biology of the virus. Like many other RNA viruses, RNA structures in coronaviruses regulate gene expression and are crucial for viral replication. Although genome and transcriptome data were recently reported, there is to date little experimental data on native RNA structures in SARS-CoV-2 and most putative regulatory sequences are functionally uncharacterized. Here we report secondary structure ensembles of the entire SARS-CoV-2 genome in infected cells at single nucleotide resolution using dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) and the algorithm ‘detection of RNA folding ensembles using expectation–maximization’ clustering (DREEM). Our results reveal previously undescribed alternative RNA conformations across the genome, including structures of the frameshift stimulating element (FSE), a major drug target, that are drastically different from prevailing in vitro population average models. Importantly, we find that this structural ensemble promotes frameshifting rates (~40%) similar to in vivo ribosome profiling studies and much higher than the canonical minimal FSE (~20%). Overall, our result highlight the value of studying RNA folding in its native, dynamic and cellular context. The genomic structures detailed here lays the groundwork for coronavirus RNA biology and will guide the design of SARS-CoV-2 RNA-based therapeutics.Competing Interest StatementThe authors have declared no competing interest.